 
 (defn- get-avg-gran-size
   "Gets SizeEstimation value for AverageSizeOfGranulesSampled and parses it to a number."
-  [vars]
-  (let [value (get-in (first vars) [:umm :SizeEstimation :AverageSizeOfGranulesSampled])]
-    (if (string? value)
-      (read-string value)
-      value)))
-
-(defn- get-avg-compression-rate
+  [variable]
+  (-> variable
+      (get-in [:umm :SizeEstimation :AverageSizeOfGranulesSampled])
+      read-number))
+
+(defn- get-avg-compression-rate-ascii
   "Gets SizeEstimation value for AvgCompressionRateASCII and parses it to a number."
-  [vars]
-  (let [value (get-in (first vars) [:umm :SizeEstimation :AvgCompressionRateASCII])]
-    (if (string? value)
-      (read-string value)
-      value)))
+  [variable]
+  (-> variable
+      (get-in [:umm :SizeEstimation :AvgCompressionRateASCII])
+      read-number))
+
+(defn- get-avg-compression-rate-netcdf4
+  "Gets SizeEstimation value for AvgCompressionRateNetCDF4 and parses it to a number."
+  [variable]
+  (-> variable
+      (get-in [:umm :SizeEstimation :AvgCompressionRateNetCDF4])
+      read-number))
 
 (defn estimate-dods-size
+  "Calculates the estimated size for DODS format."
   [granule-count variables]
   (let [compression 1
         metadata 0 ; included here for symmetry

;;; Note that all internal operations for estimating size are performed
;;; assuming bytes as the units.

(defn- get-measurement
  [variable]
  (let [dims (get-in variable [:umm :Dimensions])

              {:errors (errors/check
                        [not data-files metadata-errors/empty-gnl-data-files])})

        params (assoc params :total-granule-input-bytes (:total-granule-input-bytes raw-params))
        fmt (:format params)]
    (log/trace "raw-params:" raw-params)
    (log/debug "Got format:" fmt)
    (log/debug "Got data-files:" (vec data-files))
    (log/debug "Got services:" services)
    (log/debug "Got vars:" vars)
    (log/debug "Got total-granule-input-bytes:" (:total-granule-input-bytes raw-params))
    (process-results
      {:params params
       :data-files data-files
